¶1The property known as Bass Rock is an outcropping of 38,200 square feet of rock and ledge located at the end of Bass Rock Lane in Marblehead (the locus). When Robert W. Rose conveyed the locus to Morris Tobin by deed dated April 12, 1971, and recorded on July 16, 1971, he reserved for himself, his heirs, and assigns “the right to pass and repass over said property, to fish from the rocks and generally to enjoy the benefits of said property in common with *30others.” The deed recites that the conveyance is for nominal consideration.
¶2The defendant Lilly is now the record owner of the locus; the defendant Sokolow is the grantee of an unrecorded deed of the locus from Lilly. The plaintiff Carol Rose Burritt is the daughter, and heir, of Robert W. Rose, and the remaining plaintiffs are the children of Burritt.
¶3Sokolow seeks to construct a residence on the locus.
¶4Discussion. The proposed residence is shown on a plan dated June 9, 1992. The plan shows that the residence would be above the soil line and would occupy a “footprint” of about 560 square feet. The plan also shows a concrete walk extending from the end of Bass Rock Lane across a portion of the locus to below the soil line, together with masonry stairs, both of which are designed to facilitate access to the locus for those having easement rights.
¶5The judge made these findings about the locus:
¶6The judge concluded that these unspoiled areas jutting into *31the sea are the “ ‘benefits of said property’ [referred to in the easement], and they would be materially interfered with by the proposed residence and its parking areas.” The judge entered a final judgment which (i) adjudged that the easement set forth in the deed to Tobin “may [be] exercise[d]. . . over the entire area conveyed under said deed and said area shall be kept in its natural state” and (ii) enjoined the defendants from constructing the proposed residence on the locus, “and from otherwise disturbing the natural state of said area.”
¶7The judge’s finding that there was no genuine issue as to any material fact apparently was based on his conclusion that the Tobin deed was “not ambiguous.” However, the documents on file in the case include the affidavit of Richard Sokolow to which is attached a copy of a letter from Carol Rose Burritt to Tobin, dated May 18, 1976, five years after the date of the deed to Tobin. That letter states, “My father discussed the best solution for the land . . . [deeded to To-bin], With my approval it was deeded to you by my father for your use and not to be held for the family"
¶8The 1976 letter from Burritt to Tobin, which the judge ruled was not relevant because the Tobin deed was not ambiguous, as well as the underlying conversation between Burritt and Rose,
¶9*32We conclude that there is a genuine issue as to a material fact — whether Rose intended his deed to a third party, To-bin, to be the means by which the natural state of the property would be preserved, as the plaintiffs claim, or whether the Tobin deed was intended to permit Tobin to make use of the locus, including construction upon it, while preserving the right of the heirs to go upon the property for the purpose of viewing and enjoying the ocean scene, as Sokolow claims. The issue of Rose’s intention is critical to the outcome in this case. See Ellis v. Wingate, 338 Mass. 481, 485 (1959).
¶10In these circumstances we hold that the stipulation of the parties was improvidently entered into and the judge should not have accepted the stipulation as binding upon him. See Granby Heights Assn., Inc. v. Dean, 38 Mass. App. Ct. 266, 269 (1995) (a court may vacate a stipulation made by the parties if it is deemed “improvident or not conducive to justice”), quoting from Loring v. Mercier, 318 Mass. 599, 601 (1945) (an appellate court as well as the trial court may vacate an improvident stipulation).
¶11Because this case must be remanded to the Land Court, we offer certain guidelines, which the trial judge may find helpful.
¶12The judge divided the easement into separate components (the right to pass and repass over said property; the right to fish from the rocks — as to which there is no dispute; and the right to enjoy the benefits of the property in common with others), analyzing each component separately. We disagree with this mode of analysis. The right to pass and repass over the property together with the right to enjoy the benefits of the property would seem to be united by a single intention of the grantor. Whatever was intended by the grant of the right to enjoy the benefits of the property, the right to pass and repass merely provided specific assurance that that right of *33enjoyment would be available without trespassing upon the property of another.
¶13We also emphasize that what the plaintiffs seek in these proceedings is similar to a negative easement, that is, it resembles a covenant by Rose that the locus will not be built upon and will be kept in its natural state.
¶14Finally, we observe that the right to an injunction against the obstruction of an easement “is not an absolute one.” Perry v. Hewitt, 314 Mass. 346, 350 (1943). It is important to consider whether the intrusion upon the easement is serious or substantial. Ibid.If, for example, the rights reserved by the easement are deemed to require, consistently with the intention of the grantor, merely enforceable assurances that access to those portions of the locus that afford the beneficiaries of the easement the enjoyment of “just watching the ocean from the area at the end of Bass Rock Lane,” as described in Carol Rose Burritt’s affidavit,
¶15The judgment is reversed, and the case is remanded to the Land Court for further proceedings.
¶16So ordered.
¶17The Marblehead planning board approved a site plan special permit for Sokolow’s proposed house.
¶18The judge stated that in prior proceedings involving Bass Rock he had viewed the locus. Those proceedings involved the defendants but not the plaintiffs. We need not consider whether it was appropriate for the judge, in considering a motion for summary judgment, to include his impressions from the view, see Berlandi v. Commonwealth, 314 Mass. 424, 451 (1943) (information acquired on a view may be treated as evidence), for nothing turns on that fact.
¶19There is also on file the affidavit of Carol Rose Burritt, dated October 25, 1991, which states that her father told her that “by deeding the property to Attorney Tobin he was guaranteeing that it would never be built upon.”
¶20At the trial, the parties will be obliged to consider whether, or the extent to which, Burritt’s conversations with her father are admissible. See G. L. c. 233, § 65, regarding declarations of deceased persons.
¶21Without denying or referring to the judge’s statement that the parties stipulated that there was no genuine issue of a material fact, Sokolow, in this court, seeks a remand for trial on the merits, relying on the claim that the filed affidavits are directly contradictory as to Rose’s intention in conveying the locus to Tobin. We are not unmindful of the rule that parties may not change the theory on which, by assent and with the approval of the judge, the case was tried. See Commonwealth v. Johnson, 374 Mass. 453, 465 (1978); Larson v. Larson, 28 Mass. App. Ct. 338, 341 (1990). Nevertheless, we conclude, for the reasons stated in the text, that this rule must yield to the need to consider the argument made on appeal.
¶22Illustrations of a negative easement may be found in Myers v. Salin, 13 Mass. App. Ct. 127, 134 n.9 (1982). There is some authority that a negative easement is always an appurtenant easement — a condition that does not exist in this case. See 2 American Law of Property § 8.12, at 237 (Casner ed. 1952). Section 8.12 explains that the “interest protected by a negative easement is always an interest in the enjoyment of land possessed by the one entitled to the benefit of the easement.”
¶23The affidavit states, “During the last several years I have come to Marblehead at least once each year and have gone on Bass Rock and have greatly enjoyed just watching the ocean from the area at the end of Bass Rock Lane. Those moments are very precious to me.”